Using a medical device that doesn’t have 510(k) clearance is like operating a vehicle without a license

While you CAN drive without a license, you may not be safe and competent to be on the road.  And, if caught, you may be subject to penalties.

During recent customer visits, we became aware that many blood banks don’t clearly understand the significance of the FDA 510(k) clearance for medical devices – including users of Safe-T-Vue temperature indicators.  In this VUEPOINT, we explain what the 510(k) is, why it matters, and how you can know if a product that you are using has been cleared by FDA 510(k).

What is the FDA Section 510(k)?

The purpose of the FDA is to oversee the safety of food and medical products in the US. Much of the FDA’s authority is derived from the Federal Food, Drug & Cosmetic Act. Section 510(k) of the act requires manufacturers to notify FDA prior to marketing a new, non-exempt medical device.  As a result, this premarket notification is called a 510(k) submission.  A 510(k) submission is made to the FDA to demonstrate that the medical device is substantially equivalent to another legally marketed medical device, called a predicate device.  Substantially equivalent means that the device is at least as safe and effective as the predicate device.  FDA reviews 510(k) submissions and determines if the medical device is substantially equivalent or not.  If the FDA determines that the device is substantially equivalent , then the device is considered “510(k) cleared”.

Screenshot of FDA website to Search Medical Device DatabaseThis FDA requirement applies to medical devices including temperature indicators for blood and is of critical importance.  510(k) clearance shows that the FDA has reviewed the data and found the device to be as safe and effective as another 510(k) cleared device already on the market.

Just because a product is being sold into the healthcare market, do not assume it has been cleared by FDA.  Ask your supplier – and make them prove it.

Think of the 510(k) like a driver’s license.

If a person operates a motor vehicle without a driver’s license, they are not only in violation of the law; you have a potentially unsafe driver milling about among those who are legally licensed.  The unlicensed driver may not have passed the required exam or worse, had his/her license revoked due to unsafe and/or violative performance.  An unlicensed driver may be perfectly capable of safely operating a motor vehicle, but if caught, will be subject to penalty.

How does this apply to medical devices like temperature indicators?

A product that has not been cleared by FDA under section 510(k) may not have been reviewed for safety and effectiveness and therefore, does not have the legal right to be in the market.  The product may be safe and could perform quite well, but then again it may be unsafe and not meet its stated performance criteria.   The 510(k) clearance gives you some assurance that the product has been reviewed by the FDA and determined to be as safe and as effective as other legally marketed devices.

What else can you do to assure that medical devices you are using in your lab are safe and effective?

Quality Audits

In addition to 510(k) clearance, credible suppliers have a quality plan to support the process and accuracy claims of their products.  For example, actual and statistical verification of Safe-T-Vue data supports the product claims.  As part of the quality plan, this data is reviewed by the company’s QC staff and annually by external auditors.

Origin of the Medical Device

The 510(k) authorizes the FDA to inspect manufacturing facilities, providing additional assurance that the product you are purchasing – and trusting – is manufactured within quality guidelines and best practices.  As an example, a product that has not met 510(k) clearance could be manufactured in a facility that also manufactures garments, without quality oversight.  Know where your product is manufactured and if that facility has been inspected by the FDA.


Going back to the driver’s license analogy, look to your suppliers of medical devices – including temperature indicators – to provide proof of their FDA 510(k) clearance.  If it is not clearly represented on the product packaging, website or literature – ask them.

How can you monitor CORE blood bag temperature with adhesive temperature indicators?

With several indicators on the market, it’s increasingly confusing to know what to use – or who to trust.

There’s been a lot of “buzz” lately about measuring core temperature of blood units during temporary storage and transport.  Do the adhesive temperature indicators on the market, including Safe-T-Vue, measure core temperature?

The simple answer is NO.

Since all of the available temperature indicators are applied to the blood bag surface, they do not measure core temperature. As most of you know, there is no way to measure core temperature of a blood unit during temporary storage and transport without inserting a temperature probe into the “core” of the bag.

So, if the indicators aren’t sensing core temperature, what are they sensing?

These adhesive temperature indicators are actually measuring the surface temperature of the bag, not core temperature.  Safe-T-Vue also measures the surface temperature of the bag. However, through over 20,000 laboratory tests, we have developed direct correlations between blood bag surface temperature and core blood product temperatures.  This process allows us to formulate a consistently performing adhesive surface indicator, and assures that Safe-T-Vue indicator response is accurately correlated to actual core temperatures.

How can you trust the performance of a temperature indicator?

1. Published product specifications

Suppliers, like William Labs, publish the temperature accuracy of their products, usually in their product literature and on their websites.

Safe-T-Vue has correlated temperature indication to core blood bag temperature supported by over 20,000 test data results that quantitatively support the consistency, predictability and repeatability of its indicator performance.

2. QA Documentation

Some suppliers take the “proof” of temperature accuracy a step farther, by supplying their customers with QA documents and procedures, documenting the temperature data for that product, for each lot, to prove that testing was performed and the product performs to specification.  Safe-T-Vue is shipped with accompanying QA documents, which can also be accessed anytime from our website.

For added confidence and convenience, the validation procedures for Safe-T-Vue are published on the website, for those users who would like to perform their validations and replicate our work in their own labs.

3. FDA 510(k) and Quality Audits

As you know, the purpose of the FDA is to oversee safety.  Section 510(k) helps the FDA make sure new medical devices are safe and effective. New medical devices submitted under 510(k) rules must also be “substantially equivalent” to other similar marketed products.

This FDA regulation that applies to medical devices, including temperature indicators, is of critical importance.  It assures that the supplier of the product you are trusting to “do its job” is both safe and effective.  510(k) ensures the product is as safe and as effective as other 510(k) devices already on the market.

Just because a product is being sold into the healthcare market, do not assume it has been cleared by FDA 510(k).  Ask your supplier – and make them prove it.

Additionally, credible suppliers have a quality plan to support the process and accuracy claims of their products.  For example, actual and statistical verification of Safe-T-Vue data supports the product claims.  As part of the quality plan, this data is reviewed by the company’s QC staff and annually by external auditors.

What’s next?

We’ve been so stimulated by the recent conversation about core temperature, that we’re making plans now for comparative studies in early 2014, which we will be sharing with you.  Our new partnership with Temptime has expanded our time-temperature testing capabilities and laboratory expertise in healthcare, so look forward to these and other test results in the coming year.

As always, if you have any thoughts on core temperature measurement and adhesive temperature indicators, we always appreciate hearing from you.  Feel free to post a comment on the VUEPOINT post, or email us.

When should I use a probe for temperature validations?

Here are a few guidelines for validation with or without a probe, based on what you told us

With our daily giveaway contest of a Val-A-Sure Cooler Validation Kit at AABB, we had the opportunity to talk with many of you about the validation procedures in your blood banks. Hands down, the most frequently asked question was “when do I use temperature recorders with external temperature probes – and when should I use temperature recorders with built-in sensors?”  Our Advantage Kit is configured with both types, since our research showed us that it’s done both ways for a number of reasons.

When we conducted product development beta tests and interviews with your peers, we learned a lot.  Here are a few guidelines for validation with or without a probe, based on what you told us.

Using Built-In Sensor Temperature Recorders

  1. When temperature among, around or between the bags in the cooler are to be recorded
  2. When several points within the cooler need to be recorded
  3. Where the compactness of the built-in sensor makes it easier to fit into the cooler/space
  4. In a larger cooler with six or more bags and numerous areas within the cooler need to be recorded, such as near top, near bottom, sides and ends
  5. General monitoring of all sizes of refrigerators, freezers, and ovens

Using Temperature Recorders with Probes

  1. When core temperature of blood bags is to be recorded
  2. For larger coolers where specific, more pin-point locations need to be temperature-monitored
  3. General monitoring of all sizes of refrigerators, freezers, and ovens where the probe may or may not be in a liquid

The Val-A-Sure Advantage Kit is supplied with 2 TRIX-8 Recorders (built-in sensors) and 2 TREX-8 Recorders with Bag-Sealer Probes. For those of you who prefer different recorder configurations, the Custom Kit allows you to select exactly the type and quantity of temperature recorders that will work best for your needs.

The temperature recorders have a range of +85 to -40°C, and we’re learning that some labs are using them for validations beyond transport coolers.  Every recorder is supplied with calibration document identifying instruments used for calibration and their traceability to a NIST standard.

If you have any other guidelines or suggestions to share, please feel free to Comment on this post (below) and we’ll be sure to pass it on to your peers!

And don’t forget, we have validation procedure videos here on the William Labs website.

How can you have confidence in blood temperature compliance during transport?

This video illustrates how easily blood products can be out of temperature compliance during transport. Perhaps the blood was not packed properly, or the units were exposed to higher temperatures before being returned to safe temperatures.  How do you know that it has been maintained at 10°C per AABB standards? How can you control quality?

Safe-T-Vue® 10 can be used to promote safe blood management temperatures when the blood is out of the blood bank. It is a temperature-sensitive indicator that easily adheres directly to blood bags during transport and temporary storage. It is ideally suited for use by blood banks and transfusion services to maintain quality control in transport and storage of blood, and other temperature-sensitive products.

Safe-T-Vue 10 changes color from white to red when the 10°C indication temperature has been reached or exceeded. Because it is nonreversible, Safe-T-Vue 10 will indicate that an unsafe temperature condition existed, even if the temperature returns to a safe level. As long as the indicator remains white, blood may be safely reissued. Safe-T-Vue 10 is easy to activate and simple to interpret with clear visual indication.

These Nonreversible Temperature Indicators for Blood Products and Temperature-Sensitive Biologicals can be used for:

  • Red Blood Cells, Whole Blood, Packed Cells, Plasma, Vaccines and Specimens
  • Transport Containers and Pneumatic Tube Systems
  • Specific visual indication that blood products may be reissued when returned – per American Association of Blood Banks (AABB) Standards for Blood Banks and Transfusion Services and 21 CFR 600.15(a)

Blood Temperature Compliance at 6°C … is it safe to re-inventory?

When blood products are issued from the blood bank in a packed cooler and are later returned to the blood bank, how do you know if the blood was maintained at the compliance temperature of 6°C? In this 90 second video, you’ll see how Safe-T-Vue® 6 from William Laboratories ( can be used throughout the transport and temporary storage process to provide easy visual indication if the blood temperature exceeds 6°C.

Val-A-Sure Cooler Validation Kit Overview & Introduction

The Val-A-Sure™ Cooler Validation Kit from William Labs ( combines everything you need in one simple kit for temperature validation of blood transport coolers. All of the necessary components, instructions and documentation for validation are conveniently included in the kit, and have been tested to work together efficiently and accurately.Hands-on trials and feedback from blood banks and laboratories provided the guidance for the Val-A-Sure™ kit development. It delivers the simplicity, accuracy, standardization and speed of process that blood banks and labs told us that they need — in one integrated kit.

Recommended SOPs, temperature recorders and software provide options for an accurate validation process, regardless of your blood bank size. Using electronic recording equipment and following the SOPs, and using the supporting documentation, helps ensure consistent measurement and recording for each validation.

The DVD and documentation supplied with the kit contain:

– QuickStart Guide
– Easy-to-follow 3 minute video instructions of 3 different recommended validation procedures
– Validation SOPs (4 included)
– Validation Log Sheet
– Cooler Label format/template
– Validation Tips

Should you return the blood to inventory?


Infographic Transport William Labs

Assuring temperature compliance during blood product transport and storage has been a topic of concern and debate for quite some time.

We know that the coolers validated and blood is properly packed when it’s issued, but are you confident that the blood was kept in the cooler, or left out where it could warm above the temperature limit?  Do you worry about what could have happened while the blood was NOT in your control?

This infographic illustrates this process and the challenges it presents, and shows how temperature indicators can be used to assure that out-of-compliance blood products do not get re-inventoried.

Simulating Platelets for Validations

Guidance in using an average density to simulate platelets for validations

After reading our VUEPOINT post – “Simulated Blood Products: 10% Glycerol in water may NOT be “One Size Fits All” – that presented “recipes” for simulated blood products (Red Blood Cells, Whole Blood and Plasma) – one of our VUEPOINT readers recently  posted a comment on our website. The question was about platelets, asking for the water-glycerol mixture for simulating them, just like we had done for the other blood products. Great question and we’re glad you asked!

How do we calculate an accurate mixture based on varying platelet densities?

Because of the density range of platelets, if you were striving to be highly, highly accurate, you would need to know what group the platelets fall into. Various professional papers discuss high, low and other density groups. Here is a reference from the University of Virginia School of medicine that classifies platelets into three Density Classes, with an average density for each class.

Another platelet density analysis reported “…normal platelets layered onto Percoll formed a band extending from 1.0625 g/ml to 1.0925 g/ml, with a mean platelet density of 1.0775 g/ml:…”.1

In response to our VUEPOINT reader’s inquiry, we have modified our graph and recommended water-glycerol mixture (1.066, 26%) to include a formula for platelets. This graph plots the % Glycerol (y-axis) to Density / Specific Gravity (x-axis), which reflects density, for Plasma, Whole Blood, Platelets and RBCs.

Recommended “Recipes” for simulated blood products

Based on the data presented in this VUEPOINT, we recommend that you consider using the following mixtures for blood product simulation.

Stir for a few minutes to assure a homogeneous solution. Be sure to follow any precautions supplied by the glycerol manufacturer for handling pure glycerol.

Other Sources for Platelet Density Information

For those of you who are interested in digging a little deeper into platelet density, here is a link to another reference that reports blood density determination:
Blood. 1977 Jan;49(1):71-87. Heterogeneity of human whole blood platelet subpopulations. I. Relationship between buoyant density, cell volume, and ultrastructure. Corash L, Tan H, Gralnick HR.

Please Share Your Questions and Feedback

We always appreciate questions like these that give us an opportunity to do some research and share more valuable information, with the goal of making your job a little easier if we can. Please don’t hesitate to post a COMMENT to any of our VUEPOINT articles if you have something to share, or would like to us to “dig a little deeper” for our mutual learning.

1 Platelet-Density Analysis and Intraplatelet Granule Content in Young Insulin Dependent Diabetics, A. Collier, H.H. K Watson, D.M. Matthews, L. Strain, C.A. Ludlam, and D.F. Clarke, Diabetes, Vol. 35, October 1986.

Simulated Blood Products: 10% Glycerol in water may NOT be “One Size Fits All”

In your validation procedure, are you using the right mixture to simulate Plasma, RBCs and Whole Blood?

It would be reasonable to say that the common practice has historically been to use a 10% glycerol in water (by weight) mixture as a substitute for blood for various reasons, including transport cooler validation. In this VUEPOINT, we’d like to share with you our exploration of how accurate that “recipe” is for different blood products – namely Red Blood Cells, Whole Blood and Plasma.

Our work in the area of transport cooler validation with our new Val-A-Sure cooler validation kit product development was a major contributor to this lab exploration. At the same time, we were also performing a periodic review of several of the instructional procedures that we use for validating our blood temperature indicators, Safe-T-Vue.

With these two projects in front of me, I decided to research the commonly used 10% glycerol in water mixture. I finally found a chart in an old CRC Chemistry and Physics Handbook* that gave the source. I was surprised to find that the 10% glycerol solution (by weight, not volume) referred to plasma and that the densities for other blood products required increasing amounts of glycerol. The difference between plasma and RBCs is about 6% in density, meaning that simulating RBCs requires three times the amount of glycerol in water to achieve the equivalent density to actual RBCs. All along we’ve been operating with “10% glycerol in water” as the “one size fits all” substitute, when it actually only accurately simulates plasma.

Why may this be important in validation procedures?

Density can typically be related to the rate of heat transfer in a medium, where higher density usually indicates a faster rate of heat transfer. Making an assumption that the rate of warming of RBCs versus plasma is 6% faster, we estimate that over 30 minutes, a bag of RBCs would reach 10°C approximately 2 minutes faster than an equivalent bag of plasma. So, to accurately simulate RBCs, a mixture of 33% glycerol in water (by weight) should be used. This graphic plots the % Glycerol (y-axis) to Density / Specific Gravity (x-axis), which reflects density, for Plasma, Whole Blood and RBCs.

You may find this information interesting as you evaluate your own validation procedures and if you are using simulated blood products, take this into consideration as you prepare your simulated units to decide if you would like to achieve a density more closely representative of the actual blood product.

This finding also leads me to the importance of having the lowest possible starting temperature for refrigerated blood, and careful packing of a transport cooler to maintain required blood product temperature during storage and transport.

Recommended “Recipe” for simulated blood products

Based on the data presented in this VUEPOINT, we recommend that you consider using the following mixtures for blood product simulation.

Notes: Stir for a few minutes to assure a homogeneous solution. Be sure to follow any precautions supplied by the glycerol manufacturer for handling pure glycerol.

Reference: Bosart and Snoddy, Journal of Industrial Engineering Chemistry 19, 506 (1927)

Stop by our booth #1211 at AABB for a handout on this and other cooler validation tips.


Val-A-Sure Cooler Validation Kit – Come check it out at AABB 2012

In January of this year, we conducted a Cooler Validation Survey, which drew participation from over 70 blood banking professionals. You and your peers were generous and forthcoming with your ideas, concerns and procedures. For that, we are genuinely grateful. Survey results >>

In response to that survey, we conducted field trials and rigorously pursued product development. The result is our new Val-A-Sure Cooler Validation Kit – which is more than a “kit” of equipment.  Our testers are most excited about the SOPs (Validation procedures), documentation and video instructions that they can use – or customize to their specific environments – to simplify cooler validation.

Please come see for yourself at AABB 2012.  You’ll find us in Booth #1211. We look forward to your visit!